A RESEARCH project carried out on Dorset's rare Greater Horseshoe bats has revealed them to be immigrants.

It turns out that the UK's population originated from West Asia around 40,000 to 60,000 years ago.

By taking tiny tissue samples from the Purbeck bats it was discovered that Greater Horseshoe bats colonised Europe before the last ice age.

Samples were taken from these incredible survivors across their range from the UK to Japan and their DNA compared.

The research was carried out in collaboration with another genetic project by Stephen Rossiter at Queen Mary, University of London, who found when the last ice age advanced the bats migrated to southern Europe along with bears, hedgehogs and grasshoppers and later returned.

Bat expert David Bullock, head of nature conservation at the National Trust, said: "We still don't know a large amount about bats, so every new fact helps us to build a better picture of the lives of these fascinating creatures.

"These findings bring us hope that they can regain their original range which they have lost in recent years," he said.

In 2005 the National Trust and partners launched the Purbeck Bat Project in conjunction with the University of Bristol, the UK's first landscape scale study into bats.

PhD researcher Jon Flanders has discovered many remarkable new facts, including two new populations of Bechstein's bats and three maternity roost trees, as well as a female Barbastelle, indicating there is at least one maternity colony in Purbeck.

A network of disused quarries has been found to be nationally important for swarming bats, with different bats using different quarries.

"My three years hanging around with bats have shown just how diverse the Isle of Purbeck is for bats," said Jon, who handled over 87 Greater Horseshoes and watched more than 90 Bechstein bats emerging from a tree roost.